URGENT Firebird Riello Motor Hot

[AlanLJ]

Hello all.

I'm looking for advice to help my heating engineer fix my problem! He actually installed the unit.
It’s a 3 year old oil boiler, a Firebird with C26 Riello burner.
It’s been running fine since installation, but went into Lockout a couple of weeks ago.
The engineer first changed the kerosene pump saying it was very stiff to turn, which seemed true actually. He also changed the nozzle. This made no difference to the problem though … still kept locking out after a few minutes.

He noticed that the motor which drives the kerosene pump was getting hot to touch after 5 minutes of use, so then changed that too. However, again this made no difference to the problem … still kept locking out after a few minutes … and the new motor also gets very hot to touch. New capacitor came with the new motor.

Frustrated, after a few days on non-use, and a very annoyed wife, I fired the boiler up myself. I noticed quite a lot of blue smoke coming from the vent, whereas previously it had always been clear, with only a hint of light colour detectable on cold days.

The engineer returned for a 3rd visit, and dealt with the blue smoke by adjusting the ‘air damper adjustment screw’ … I’m looking through the Riello manual as I type! Lol. He plugged a monitor in whilst doing this. During this 3rd visit, I know he pulled the whole Riello unit out and took much of it apart. He’s gone again now saying that he’ll have to speak with Riello. That’s fair enough.

My own little bit of diagnosis:
The boiler will fire up and continue running until something tells it to stop!
It’ll happily heat up the domestic hot water as well as the house radiators, but as soon as you start/stop a hot water tap, or it receives a signal from the Honeywell Wi-Fi thermostat (saying the house reached the desire temp), it goes into lockout.

At this point, the kerosene motor will be very hot, and you won’t be able to reset the lockout for several minutes. I’m presuming a safety temp control thermostat is causing that?

My question is: could the motor be spinning too fast, hence the reason for becoming very hot?
Could this be driving too much kerosene into the burner, hence that blue smoke?
Could it be that the new capacitor is faulty?
Or perhaps something’s simply gone wrong in the Control Box?

If anyone has any ideas on this one, it would be very much appreciated!

Cheers, guys.

 

[SJB060685]

A motor burns hot if the capacitor is weak or too strong, the motor windings could be failing, or a stiff pump, bearings or fan.
Do you have a multimeter capable of measuring capacitance?

 

[AlanLJ]

A motor burns hot if the capacitor is weak or too strong, the motor windings could be failing, or a stiff pump, bearings or fan.
Do you have a multimeter capable of measuring capacitance?

Hi SJB060685.
I can only presume (and hope) that the engineer did check the capacitor. I think he replaced both the kerosene pump and the motor for a second time.
He's very experienced and professional, hence this little problem has quite upset him . . . as well as my wife who can't dry the washing on the radiators! Lol.
As you say, it might be the fan that's failing too. Just seems odd that the boiler will run until interrupted, at which point it locks out, and needs to cool down
before accepting a reset.
Very many thanks for your help.
Cheers.
Alan.

 

[SJB060685]

The burner control box has no way of telling if the motor is running too hot. There is no temperature sensor that would cause a control box lockout. Any chance of a video showing the burner going through its relight cycle?

 

[AlanLJ]

The burner control box has no way of telling if the motor is running too hot. There is no temperature sensor that would cause a control box lockout. Any chance of a video showing the burner going through its relight cycle?

Thanks again, SBJ060685.
I'll try to do that asap. Just to say, there are no unusual noises, and the start-up cycle sounds quiet and normal ... to the uninitiated such as me!

 

[SJB060685]

With the boiler running try and initiate an interuption by turning the boiler stat down, the burner will shut down, then turn the dial up and be recording the burner so I can see and hear what the burner is trying to do please.

 

[AlanLJ]

Thanks again, SBJ060685.
I'll try to do that asap. Just to say, there are no unusual noises, and the start-up cycle sounds quiet and normal *** to the uninitiated such as me!

I've fired up the boiler this evening, and made a few videos of each startup; that being, it did of course go into lockout a few times, and
therefore require a reset several times.
The motor is hot, certainly, but perhaps not unbearably hot?
I do stand corrected on one important point though: it appears it doesn't need any form of interrupt to cause it to lockout, i.e. using a hot water tap, it's
quite happy to lockout on its own after 10 or 15 minutes of use. It's done this several times now.
Video to follow.

 

[AlanLJ]

I've fired up the boiler this evening, and made a few videos of each startup; that being, it did of course go into lockout a few times, and
therefore require a reset several times.
The motor is hot, certainly, but perhaps not unbearably hot?
I do stand corrected on one important point though: it appears it doesn't need any form of interrupt to cause it to lockout, i.e. using a hot water tap, it's
quite happy to lockout on its own after 10 or 15 minutes of use. It's done this several times now.
Video to follow.

 

[AlanLJ]

Oh, well! Sadly my video (1 min) was too large to upload. Not surprised I guess. :-(
Scratching my head a bit now.

 

[SJB060685]

Motors will obviously be quite hot when running at steady state, could not tell you what sort of temperatures are normal though, lots of variables can effect that.
Running for 10-15 minutes though at a time suggests possibly a fuel issue. I think the temperature of the motor is irrelevant to your lockout problem now.
See if you can get a shorter video of flame failure and retry cycle, that would help.

 

[AlanLJ]

Motors will obviously be quite hot when running at steady state, could not tell you what sort of temperatures are normal though, lots of variables can effect that.
Running for 10-15 minutes though at a time suggests possibly a fuel issue. I think the temperature of the motor is irrelevant to your lockout problem now.
See if you can get a shorter video of flame failure and retry cycle, that would help.

Thanks again, SJB060685.
To his credit, the engineer did visit again yesterday, 8:30pm! I was working, but my wife says he checked connections etc., and is himself quite
frustrated by this problem. He's still trying to contact particular people at Firebird and/or Riello. Btw, once in lockout, we get an on/off flashing red
from the control box ... 'Lockout for false flame or parasite flame signal'. This will only reset after several minutes of cooling down. Wondering if I should
buy a replacement capacitor (long-shot) just to see if it helps! I've checked btw that the old and new capacitors have exactly the same ratings: 4,5.

 

[SJB060685]

False flame signal or parasitic light as they call it in the manuals could be caused be either faulty photocell or the control box itself. It could also it's actually detecting false light on prepurge cycle.
Based on the above you've just now said i don't think the capacitor is contributing to the fault but as I said in my original response a faulty capacitor can cause the motor to run hotter. Basically if a capacitor is weak or a larger microfarad cap is used you will get an Imbalance between the pole magnetic fields within the stator, this causes the motor to stutter, or even stall completely. If the motor is stuttering it will draw more current than in usual steady state operation and as a result runs hotter. There's two ways to test a capacitor but the one that would tell us just what the capacitance rating of the cap is requires a multimeter that can read capacitance. If you were to get a reading of 70% or less than the original 4.5uF then capacitor should be replaced. One way of getting an idea if the capacitor is struggling is when there's a demand at the burner, if the motor spins instantly it's ok but if there's a slight lag that is an indication it needs replacing.

 

[AlanLJ]

Thanks again, SJB060685.
To his credit, the engineer did visit again yesterday, 8:30pm! I was working, but my wife says he checked connections etc., and is himself quite
frustrated by this problem. He's still trying to contact particular people at Firebird and/or Riello. Btw, once in lockout, we get an on/off flashing red
from the control box ... 'Lockout for false flame or parasite flame signal'. This will only reset after several minutes of cooling down. Wondering if I should
buy a replacement capacitor (long-shot) just to see if it helps! I've checked btw that the old and new capacitors have exactly the same ratings: 4,5.View attachment 64233

 

[SJB060685]

See as soon as you press the lockout reset button and you hear it click inside the control box that motor should spin. As I mentioned above and as the video you just shared demonstrates there is a lag/delay. This could be the capacitor but it could also be the control box, sticking pump, fan, bearings. If the pump is new that shouldn't have any tight spots but it's not uncommon for parts to be faulty off the shelf. Also a tip for you and your engineer is everytime a new pump is installed replace the capacitor at the same time. The motor is new as well, so again the bearings should be fine and if the fan was catching you would almost certainly hear it rubbing against the fan housing.

As it stands I think possibly a control box giving you a couple different problems, or one problem in the false light situation and possibly the capacitor. The photocell could also cause parasitic light failures.
I appreciate your engineer has gone above and beyond for you and I'm not slating him in anyway, he's obviously tried and frustrated he's become stuck but control boxes, pumps, cells, capacitors etc should all be van stock.
Again you need a way of reading the capacitance value of a capacitor to determine its rating in uF, without it you just be guessing.

 

[AlanLJ]

View attachment 64235

Managed to upload this short video ... 22 secs.
I like the idea of a faulty photocell, as this might explain (I think) why a 'cooling down' period is required after those 10 - 15 minutes of burn time, before each lockout. We have to bear in mind though that the whole system was running fine until that initial lockout some 2 weeks ago.
The engineer reckoned the kerosene pump was too stiff, and so replaced it. I still have it as a souvenir, and sure enough, you can't turn it with the fingers.
Perhaps though, that wasn't related to the real reason for that initial lockout?
Also, wondering if the fire cut-out device (on the in-coming oil-line) is kicking in and depriving the boiler of oil?
Cheers.

 

[SJB060685]

If you can you can freely spin the old pump by hand without any tight spots then I highly doubt that needed changing.
If the fire valve was cutting in to stem oil flow then it would need to be manually reset. You haven't mentioned needing to do this, therefore that is not the problem.
Unfortunately anything can develop a problem at any time, even boilers kept in immaculate condition and serviced regularly will develop problems and unfortunately for you photocells and control boxes are very common faults on Riello burners.

 

[AlanLJ]

See as soon as you press the lockout reset button and you hear it click inside the control box that motor should spin. As I mentioned above and as the video you just shared demonstrates there is a lag/delay. This could be the capacitor but it could also be the control box, sticking pump, fan, bearings. If the pump is new that shouldn't have any tight spots but it's not uncommon for parts to be faulty off the shelf. Also a tip for you and your engineer is everytime a new pump is installed replace the capacitor at the same time. The motor is new as well, so again the bearings should be fine and if the fan was catching you would almost certainly hear it rubbing against the fan housing.

As it stands I think possibly a control box giving you a couple different problems, or one problem in the false light situation and possibly the capacitor. The photocell could also cause parasitic light failures.
I appreciate your engineer has gone above and beyond for you and I'm not slating him in anyway, he's obviously tried and frustrated he's become stuck but control boxes, pumps, cells, capacitors etc should all be van stock.
Again you need a way of reading the capacitance value of a capacitor to determine its rating in uF, without it you just be guessing.

Thanks again, SJB060685.
The engineer will hopefully return on Thurs evening (when we're not at work), and I'm tempted to message him in advance to request a change of
both Control Box and Photocell . . . one at a time of course. Part-Changing exercise I know, but the whole system is too new for it to be anything more
than a simple, albeit annoying, little fault. Thanks for watching that video; your expertise is really very much appreciated.
Cheers.
Alan.

 

[AlanLJ]

If you can you can freely spin the old pump by hand without any tight spots then I highly doubt that needed changing.
If the fire valve was cutting in to stem oil flow then it would need to be manually reset. You haven't mentioned needing to do this, therefore that is not the problem.
Unfortunately anything can develop a problem at any time, even boilers kept in immaculate condition and serviced regularly will develop problems and unfortunately for you photocells and control boxes are very common faults on Riello burners.

Brilliant advice. Thank you!!!

 

[SJB060685]

Thanks again, SJB060685.
The engineer will hopefully return on Thurs evening (when we're not at work), and I'm tempted to message him in advance to request a change of
both Control Box and Photocell . . . one at a time of course. Part-Changing exercise I know, but the whole system is too new for it to be anything more
than a simple, albeit annoying, little fault. Thanks for watching that video; your expertise is really very much appreciated.
Cheers.
Alan.

I'm happy to help, obviously there's only so much that I can do through typing a message over a phone though. Oil burners is my official trade but I'm just as passionate about heating systems and electricity as well. I don't know everything, there's still a long way to go but studying is the only way someone will get there.

 

[AlanLJ]

I'm happy to help, obviously there's only so much that I can do through typing a message over a phone though. Oil burners is my official trade but I'm just as passionate about heating systems and electricity as well. I don't know everything, there's still a long way to go but studying is the only way someone will get there.

Hello again, SJB060685.
Photocell !!! That was the problem. Once you'd suggested the Control Box and Photocell as being common problems on the Riello units, I sent a text to my engineer.
He was doing his own research too, and enthusiastically returned two days ago, quickly changing the photocell. That did the trick! However, not before he'd tried a couple
of photocells . . . one being analogue and the other being digital. I'm not sure as to which one he ended up fitting, but I'll find out hopefully.
Thanks again, SJB060685. Hopefully this thread will help others too.
Best wishes.
Alan.

 

[SJB060685]

Hello again, SJB060685.
Photocell !!! That was the problem. Once you'd suggested the Control Box and Photocell as being common problems on the Riello units, I sent a text to my engineer.
He was doing his own research too, and enthusiastically returned two days ago, quickly changing the photocell. That did the trick! However, not before he'd tried a couple
of photocells . . . one being analogue and the other being digital. I'm not sure as to which one he ended up fitting, but I'll find out hopefully.
Thanks again, SJB060685. Hopefully this thread will help others too.
Best wishes.
Alan.

Glad it's sorted. The Riello burners use analogue and digital control boxes, the correct is required for each type.